Cognitive Labs

Men are red, women are green, the nose may be key to "reading" a face, and ordinary eyebrows may be what makes a face recognizable, rather than, say, provocatively bee-stung lips or baby blues. (Interestingly, in aspective Egyptian art, the convention is to show men as reddish in tone like the skin of a Spanish peanut, while women were shown in a yellowish tone, and the dead like Osiris, were green)

Those insights into how we "see" faces are part of the growing field of facial recognition, one of the hottest realms in psychology and neural science.

"It's very controversial: How do we see a face?" said Pawan Sinha, professor of vision and computational neuroscience at the Massachusetts Institute of Technology. Among the fiercely debated topics, he said, "is whether we learn to recognize faces or whether we come prewired with dedicated brainware for recognizing faces. The disagreement is deep - and rather sharp."

The focus on faces at universities and other research centers is far from purely academic. In the age of terrorism, police and intelligence agencies are clamoring for new technologies that can scan and accurately identify faces - winnow a "wanted" individual from the anonymous airport crowd, or a terrorist scoping out public buildings.

"Understanding how the brain works is the greatest mystery facing us in this century," said Garrison W. Cottrell, professor of computer science at the University of California in San Diego's Jacobs School of Engineering. "And facial recognition is among the greatest challenges to understanding the brain."

In pursuit of answers, psychologists and brain scientists have come up with some unexpected data.

Michael J. Tarr, codirector of Brown University's Center for Vision Research, recently published research in the journal Psychological Science that showed males have more reddish skin while women's skin has a greenish cast.

"The coloration is subtle, but actual - not just a trick of the mind or matter of perception. Men are redder, on average; women greener," Tarr said. "Color information is very robust."

The color difference, he theorized, may be because women need a certain skin pigmentation to better absorb ultraviolet light to synthesize vitamin B for lactation and bone development.

Meanwhile, research at the University of California in San Diego suggests people use the nose as a sort of main navigational point for charting a face.

Scientists found we focus first on the nose - looking just to the left of it, and then to the center - before deciding in a split-instant whether we recognize the person.

Other research suggests eyebrows may be as important as eyes when it comes to recognition. "Put on glasses with thick lenses or strange frames, and people will still recognize you," said MIT's Sinha, whose lab explores how the mind recognizes objects and scenes. "But shaving eyebrows is acutely disruptive to recognition."

Scientists aren't sure why, but one possibility is that eyebrows - like noses or mouths - are important because we recognize other features in relationship to them.
A very few people can be recognized by one salient feature - Jay Leno for his chin, for example. But most faces require fast mental computation," said Marlene Behrmann, professor of psychology at Pittsburgh's Carnegie Mellon University. "We are quickly measuring distances from nose to eyes, nose to mouth, eyebrows to cheek, before we recognize the face. It is these subtle relationships [of distance plus shape] that give most of us our individuality, not just our pretty nose or exquisite lips; those tend to be more similar to everyone else's than we'd care to admit."

No other object is as important for humans to recognize and interpret as faces, say scientists in the field.

"Unless you're an ornithologist, it's not important to know a robin from a sparrow; it's enough to recognize them as birds," Behrmann said. "But . . . to function in society, people have to recognize faces at a highly individualized level."

Nancy Kanwisher, a neuroscientist at MIT, is prominent among scientists whose research suggests a specific "sweet spot" in the brain - called the fusiform face area - has evolved to recognize faces. The ability is seen as coming as naturally as breathing or burping.

"Face perception may be a special domain of cognition, one with its own independent cognitive and neural machinery," she wrote recently.

But other scientists disagree, saying research points more to facial recognition as an acquired skill.

Clues to facial recognition can be found in conditions that hamper it.

Stroke victims and individuals suffering from autism have a tough time recognizing faces, as do people with a puzzling affliction called "prosopagnosia," or face blindness.

Researchers at Carnegie Mellon determined that individuals with prosopagnosia had disruptions in nerves connecting parts of the brain associated with recognizing faces.

"Most of us see the face as a whole, an assemblage. That's why you have no trouble recognizing your wife, but may not even notice her new hair style or lipstick," said Behrmann, a co-author of the study published last month in Nature Neuroscience. "People with the condition, however, can only see the parts, not the larger pattern."

Labels: eyebrows, facial, MIT, neuroscience, pawan, recognition, sinha

A new MIT study published in the Proceedings of the National Academy of Sciences, had an interesting objective: find out how much people can actually remember.

Using matched pairs of images, subjects reviewed up to 3,000 pictures over a matter of hours and were asked to identify the images they had seen earlier, with a variable sequence of mediating images they had not seen, activated by the spacebar.

While there were only 14 subjects, recall was up to 92% in some cases - suggesting that the human brain is capable of scanning, storing, and retrieving gigabytes of relational information - at least in the short term, as a form of in-resident or cached memory.

It would be fascinating to see if the relationships became distorted over time, allowing us to plot both the decay rate and obfuscation of data transfered from the cache to long term storage, answering the question of 'How reliable is memory?'

Also, finding out if the intensive exercise improved retention, which we suspect would be the case, turning back the clock on memory degradation.

Labels: 1back, MIT

Julie Steenhuysen of Reuters reports that a drug from a new class of weight-loss treatments disrupted wiring needed for brain development in young mice, U.S. researchers said on Wednesday, raising concerns about using such medications in children.

According to the piece, scientists at MIT studied the effects of a chemical that suppresses appetite by blocking cannabinoid receptors in the brain, the same brain mechanisms that make people hungry when they smoke marijuana. Evidence seems to indicate that brain development is stymied by the presence of the compound.

Read more of the article

Labels: MIT, plasticity, rinonabant

Bolstering disintegrating neural connections may help boost brainpower in Alzheimer's disease patients, MIT researchers and colleagues reported in the Nov. 8 issue of Neuron.

The researchers zeroed in on the enzymes that manipulate a key scaffolding protein for synapses, the connections through which brain cells communicate. Synapses are weakened and lost in neurodegenerative diseases such as Alzheimer's and Parkinson's disease.

"We identified a major underlying mechanism through which synapses are strengthened and maintained," said Morgan H. Sheng, Menicon Professor of Neuroscience at MIT's Picower Institute for Learning and Memory. "The enzymes involved could be good targets for potential drug treatments."

A protein called postsynaptic density-95 (PSD-95) is a key building block of synapses. Like the steel girders in a building, it acts as a scaffold around which other components are assembled. "The more PSD-95 molecules, the bigger and stronger the synapse," said co-author Myung Jong Kim, a Picower research scientist.

Previous research had shown that mice genetically altered to have less PSD-95 experienced learning and memory problems.

In the current study, the researchers identified for the first time the enzymes that work behind the scenes on PSD-95, adding a phosphate group to a specific amino acid in the PSD-95 protein. This process--called phosphorylation--is critical for PSD-95 to do its job in supporting synapses.

"Adding a phosphate group to a single amino acid allows PSD-95 to promote synapse size and strength," said Sheng, who also holds an appointment in MIT's Department of Brain and Cognitive Sciences and is a Howard Hughes Medical Institute investigator. "Therefore, promoting this process could help improve cognitive function."

Sheng believes manipulating PSD-95 through phosphorylation could lead to bigger and more robust synapses, which would boost brainpower in both normal and diseased brains. "It's possible that promoting PSD-95 phosphorylation could also help neuropsychiatric illnesses in which synapse function goes awry, such as schizophrenia, depression and autism," Sheng said.

reference: science daily

Labels: alzheimers, MIT, protein, sciencedaily, sheng

George the Robot is playing hide-and-seek with scientist Alan Schultz.

For a robot to actually find a place to hide, and then to hunt for its human playmate, is a new level of human interaction. The machine must take cues from people and behave accordingly.

This is the beginning of a real robot revolution: giving robots some humanity.

"Robots in the human environment, to me that's the final frontier," said Cynthia Breazeal, robotic life group director at the Massachusetts Institute of Technology. "The human environment is as complex as it gets; it pushes the envelope."

"Robots have to understand people as people," Breazeal said. "Right now, the average robot understands people like a chair: It's something to go around."

The places we will first see these robots that can connect with humans in a more "thoughtful" way are in the most human-oriented fields - those that require special care in dealing with the elderly, young and disabled.

As a machine, George is not a breakthrough. He's an off-the-shelf robot reprogrammed at the Navy Center for Applied Research in Artificial Intelligence, which Schultz directs.

When they play hide and seek, George doesn't hide very well, and it takes him longer to find Schultz than vice versa, but it's the fact that he does either that makes him special.

"We have only scratched the surface," said Sebastian Thrun, the Stanford Artificial Intelligence Lab director who won the Defence Department's Grand Challenge for a self-driving robot car through the desert last year. He predicted that 10 years from now robots will roam the health care system and that in our homes, multi-armed robots will be doing the cleaning. "There will be a lot of personalized devices," he says.

That's a big switch. The latest commercial home robots - the vacuuming iRobot Roomba, and its floor-cleaning cousins - are designed to work best when people leave the room. But the promise of robots for scientists is represented by Rosie, the vacuuming robot of "The Jetsons" cartoon series.

"If Rosie is going to be around and in your face, it would be good if the interaction is natural and easy," says Rod Brooks, director of MIT's artificial intelligence lab.

So after spending decades tinkering with wiring, some roboticists started studying humans, and the new field of human-robot interaction was born. Unlike the rest of robotics, many of its leaders are women. It has social scientists, language specialists, medical doctors and even ethicists who wonder if putting robots into places like nursing homes is the right thing to do.

That's a big change from 50 years ago, when the field of artificial intelligence was created at a forum at Dartmouth University. The experts focused on puzzles and chess and skipped over concepts such as perception, a sense of where you are, what's around you and how to interact.

"They all thought perception was easy - a two-year-old could do that - but smart people play chess," said Brooks, co-founder of iRobot Corp. "They all missed it and Hollywood missed it. The stuff a two-year-old could do, that's the hard stuff."

One preschooler-type skill, the ability to take someone else's perspective, "turned out to be a very important capability that we needed on our robots so that they could really work comfortably with humans," said Schultz.

Thus, Schultz hopes in the next year or so to have a robot that could, like an old-time movie detective working a case, tail a person walking through the naval research lab campus unseen.

Similarly, researchers are working on teaching language-reasoning - not just dumping a dictionary in the robot's database - gestures and eye contact so robots can understand the many ways people communicate. At NASA, astronauts are working with Schultz and a spacewalking-prototype called Robonaut to make machines understand when an astronaut points to something and says "there."

We as humans understand that, but getting robots to put those clues together is proving to be a big leap, he said. And then there are subtle clues that humans pick up without even knowing it, such as nods and eye contact.

Research scientist Candy Sidner at the Mitsubishi Electric Research Lab in Cambridge, Mass., found that people respond better to more animated robots - those that nod, move and point. So she developed Mel, a pointing, nodding penguin robot. You nod at Mel, Mel nods back.

"It's absolutely very compelling. People tell me, 'I like Mel because he's really kind of cute,' " Sidner said.

How should a robot look? There's debate on that. On one extreme are the stroke-therapy robots of MIT scientists Neville Hogan and Hermano Igo Krebs. Those look like exercise machines with video game screens. They guide the arms and legs of paralyzed stroke patients through physical therapy, and the patients don't even realize they are robots.

On the other end of the spectrum are David Hanson of Dallas and Osaka University's professor Hiroshi Ishiguro whose robots look creepily human. Ishiguro's robot Geminoid looks just like Ishiguro.

Such uncanny resemblances have led roboticists to coin the term "uncanny valley" syndrome. It suggests that people respond better to robots the closer they resemble humans - up to a point. If the resemblance is too good, people "are weirded out," Sidner said. At that point, acceptance plummets. That's why Sidner prefers her penguin robot.

Sherry Turkle at MIT worries about robots that seem too human.

"We're cheap dates," she says. "If an entity makes eye contact with you, if an entity reaches toward you in friendship, we believe there is somebody there . . . But that doesn't mean that there is. That just means that our Darwinian buttons are being pushed."

Turkle, who directs the MIT Initiative on Technology and Self, fears people will be subconsciously tricked into giving robots more credit than they deserve. Her point is that when you are sick, hurt, or elderly, "you really do want a person," not a robot.

Unfortunately, there's a shortage of people working in nursing homes and caring for old people and the disabled, said Maja Mataric, director of the University of Southern California's Center for Robotics and Embedded Systems. The average stroke victim gets 39 minutes of active exercise a day when six hours a day is needed, she said, so robots can free up the few nurses for more nurturing activities.

Mataric adjusts her robots' personalities to fit the needs of stroke patients - nurturing buddy or goal-pushing coach.

And in the case of low-functioning autistic children, they actually seem to relate better to robots than humans, Mataric said. "You'll see a child smile that has never smiled before. No one knows why it happens."

The scientists trying to engineer robots to work with humans are learning more than they expected. They have a new appreciation for our own unique abilities.

Said Deb Roy, director of MIT's Cognitive Machines Group: "It's not until you try to build a machine that does the same task (that people do) . . . that you realize how incredibly hard it is."

Let Hal test your memory

Labels: cognitive, hal, hanks, heuristic, MIT, uncanny_valley